Radio loud-speaker



F. R. SHAW RADIO LOUD SPEAKER 2 Sheets-Sheet 1 Filed March 21, 1928INVENTOR Frederick R. S haw May 27, 1930. F. R. SHAW 1,760,577

' RADIO LOUD SPEAKER Filed March 21, 1928 2 8 t h6et 2 I NVENTOR Freda[0K R. S h aw Patented May 27, 1930 Uhlll" STATES PATENT QFFICE RADIOLOUD-SPEAKER Application filed. March 21, 1928. Serial No. 263,578.

illlS invention relates to improvenients in loud speakers for use withradio receiving sets and the like. its primary object bein! to amplifythe signal received in the teiephone piece. It is designed to be used.with a pair of standard head-phones, The head-phones being placed ontire receptacles for same on the loud speaker 21. .l the amplified si'nal will proceed from t e horn. A further object being to get the samevolume of sound with a reduced number of radio tubes, thereby mailing areceiving set more economical to construct and operate. Another obje itbeing to provide a loud speaker for operation in conjunction with acrystal set and a pair of high resistance hea -phones. \Vith thiscombination. no batteries bei 1g necessary thus providing a very cheapreceiving set.

lVith these and other objects in view as will appear as the descriptionproceeds the invention consists in the novel construction arrangement ofpar ts as hereinafter more specifically set forth claimed and shown inthe accompanying drawings fo ing a part of this present application andin which Fig. 1 is a view of the improved loud speaker.

Fig. 2 is a sectional view through the amplifier.

Fi 3 is a part sectional view of same along line A. A. of Fig. 9.

Referring more in detail to the drawin in which similar referencecharacters designate corresponding parts t nroughout the several viewsit will be seen the improved loud speaker comprises a horn 10 of theusual type which is fitted into a horizontal. tone arm 11 supported upona. base 12 of substantial heavy design to give stability to the speaker.Each end of the tone arm is enlarged to the shape shown at 13 into whichare fitted the cylinder shells 14. and are secured thereto by springclips 15. 16 is a mica diaphragm being supported by an inner ring 17 andan outer ring 18, said inner ring 17 being slightly larger in crosssectioned diameter than the outer ring 18, this gives the diaphragm 16 aslightly convex shape. Secured to the center of the diaphragm 16 is aconical shaped member 19 being made preferably of carbon granules orsome graphite composition substitute and having brass stem 20 throughcenter one end of which is threaded and passed through the diaphragm 16and secured thereto by a nut 21. The function of the cone-shaped member19 to transmit the sound impulses, emitted from the diaphragm of the henlphones, to the diaphragm 16 of the loud speaker.

The impulses of the sound potential actuate resistance vibrations in thecarbon granules, similar to an electric impulse, these resistancevibrations varying a cording to the intensity of the sound wave pressureon the carbon In turn, these resistance vibrations, as rcg'stered on thecaroon granules, are actuated through the medium of the brass stem 20,to the diaphagm of the loud. speaker, and th resultant audibilityeffected in the horn of the loud speaker. A rubber gasket 22 is providedto form a cushion between the shell 141- and the diaphragm 16 the springclips 15 providing the required tension on said gasket and diaphragm.Inside the shell 1 1 is a funnel shaped member 23 preferably ofcelluloid secured at its outer edge to the shell. Fitted into theenlarged end of the shell and s cured thereto is a semiflexible rubberflange 241 having an inwardly disposed central hole 25. The face of saidflange being convex in form to lit the earphone pieces which are to beplaced therein and on account of its flexibility will allow them to itsnug into the enlarged end or receptacle of the shell 14.

t will be seen from the foregoing that the loud speak-er is controilcdfrom the headphones placed into the receptacles for the same, and thatthe diaphragm of the loud si iealrer is actuated by the movement of thediaphragm of the phone piece.

It is believed that the construction and advantages of the structureshown may be ap parent from the foregoing paragraphs taken inconjunction with the accompanying drawings without further detaileddescription.

\Vhile tire preferred embodiment of the invention has been disclosed itis understood that minor changes in the details of construction,coi'nbination and arrangement of co operating elements may be resortedto Within the scope of What is claimed Without de parting from thespirit of the invention.

What I claim is 1. In a radio loud speaker having a horn, a base, ahorizontal tone arm connecting With said horn having enlargements ateach end, a shell adapted to. fitsaid enlargement forming an earphonepiece receptacle, spring clips to secure the shell in position and adiaphragm yieldably supported in the enlarged end of the tone arm.

2. In a radio loud speaker naving a horn, a base, a horizontal tone armconnecting with said horn having an enlargement at each end,

a shell adapted to fit said enlargement forman earphone piecereceptacle, spring clips to secure the shell in position, a diaphragmyieldahly supported in the enlarged end of the tone arm, a cone-shapedmember made up of carbon granules rc-inforced With a metal stem andmeans for securing said cone-shaped member to said diaphragm.

3. In a radio load speaker having a horn, a base, a horizontal tone armconnecting with said horn having an enlargement at each end, a shelladapted to fit said enlargement forming an earphone piece receptacle,spring clips to secire said shell in position, and a semiflexible rubberflange mounted inside said shell, said flange being convex on its outerside and designed to conform itself to the shape of earphone pieces.

In testimony whereof I eliix my signature. FREDERICK RICHARD SHAVW

